Subband-Landau-level coupling in GaAs/Ga1-xAlxAs heterojunctions.
Subband-Landau-level coupling in GaAs/Ga1-xAlxAs heterojunctions.
复制标题
GaAs/Ga1-xAlxAs 异质结中的子带朗道能级耦合。
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
Schlapp
中科院分区：
文献类型：
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作者：
Wieck;Thiele;Merkt;Ploog;Weimann;Schlapp
We study the coupling of Landau levels and electric subbands in quasi-two-dimensional electron inversion layers of modulation-doped GaAs/${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathrm{x}}$${mathrm{Al}}_{mathrm{x}}$As heterojunctions in tilted magnetic fields. We employ far-infrared Fourier-transform spectroscopy with light polarized parallel to the layers. When the subband separation ${E}_{10}$ is much larger than the cyclotron energy ensuremath{Elzxh}${ensuremath{omega}}_{c}$, we find an enhancement of the cyclotron mass due to the parallel magnetic-field component. When the subband separation ${E}_{10}$=rensuremath{Elzxh}${ensuremath{omega}}_{c}$ is a multiple r=1,2 of the cyclotron energy, we observe a resonant splitting of the cyclotron resonance. The mass enhancement as well as the magnitudes and energetic positions of the splittings are described by perturbation theory and by the triangular-well approximation of the space-charge potential. From the experimental data we determine intersubband energies and dipole matrix elements. Both depend on electron density, which we adjust by illumination with a light-emitting diode or by a gate voltage applied between the inversion layer and a front gate.
We study the coupling of Landau levels and electric subbands in quasi-two-dimensional electron inversion layers of modulation-doped GaAs/${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathrm{x}}$${mathrm{Al}}_{mathrm{x}}$As heterojunctions in tilted magnetic fields. We employ far-infrared Fourier-transform spectroscopy with light polarized parallel to the layers. When the subband separation ${E}_{10}$ is much larger than the cyclotron energy ensuremath{Elzxh}${ensuremath{omega}}_{c}$, we find an enhancement of the cyclotron mass due to the parallel magnetic-field component. When the subband separation ${E}_{10}$=rensuremath{Elzxh}${ensuremath{omega}}_{c}$ is a multiple r=1,2 of the cyclotron energy, we observe a resonant splitting of the cyclotron resonance. The mass enhancement as well as the magnitudes and energetic positions of the splittings are described by perturbation theory and by the triangular-well approximation of the space-charge potential. From the experimental data we determine intersubband energies and dipole matrix elements. Both depend on electron density, which we adjust by illumination with a light-emitting diode or by a gate voltage applied between the inversion layer and a front gate.